1. Technical Field
The present disclosure relates to a thin film transistor (TFT) substrate, in which different type of thin film transistors are disposed on the same substrate, a display device including a thin film transistor substrate, and a method of forming a thin film transistor substrate.
2. Discussion of the Related Art
With the development of an information society, demands for display devices displaying an image are increasing in various ways. In a field of the display devices, a large-sized cathode ray tube (CRT) has been rapidly replaced by a flat panel display (FPD) having advantages of a thin profile, light weight, and a large-sized screen. Examples of the flat panel display include a liquid crystal display (LCD), a plasma display panel (PDP), an organic light-emitting diode (OLED) display, and an electrophoresis display (EPD).
Each of the LCD, the OLED display, and the EPD, that are driven in an active manner, includes a thin film transistor (TFT) substrate, on which thin film transistors assigned to pixel areas arranged in a matrix are disposed. The LCD displays an image by controlling a light transmittance of liquid crystals using an electric field. The OLED display displays an image by forming an organic light-emitting element in each of pixels arranged in a matrix.
The OLED display includes self-emitting elements capable of emitting light by themselves and has advantages of a fast response time, a high emission efficiency, a high luminance, and a wide viewing angle. The OLED display, using characteristics of OLEDs having good energy efficiency, may be classified into a passive matrix organic light-emitting diode (PMOLED) display and an active matrix organic light-emitting diode (AMOLED) display.
As the development of personal electronic devices has been actively carried out, display devices have been developed as products excellent in portability and/or ability to be worn. For portable and/or wearable display devices, the display devices are required to implement low power consumption. Technologies related to display devices developed so far have a limitation in implementing low power consumption.